The invention relates to a process for removing soil contaminants, in particular for purification of ground water, and a plant used, in particular, for carrying out this process.
As a consequence of increasing environmental consciousness, attempts are being made to eliminate disclosed underground contamination, in particular by hydrocarbons. These are frequently observed on old or previous sites of chemical or petrochemical plants where little or no attention has been paid in the past to full prevention of soaking of pollutants into the soil, thus causing ground water contamination. To carry out purification of ground water here is extremely difficult. In particular, such purification measures can only be carried out long-term at considerable expense. As a rule of thumb, it can be assumed that purification of ground water takes about the same time as that over which contamination of the ground water present in the soil has occurred.
Several purification processes are already known for this purpose. One process comprises replacing the soil in contaminated areas. However, this merely results in the problem being moved to special dumps. In addition, the cost of soil replacement is extremely high. Soil washing or thermal soil treatment is also known. This process is extremely complex and cost intensive. Finally, purification by drawing off the soil air with alternate or simultaneous ground water desorption is known. Here, the contaminated soil air and the exhaust air produced on stripping the contaminated ground water are purified in activated charcoal filters. In this case, the problem is merely shifted to the activated charcoal. This must namely again be stored in special dumps. In addition, this process is very time consuming. It also requires high equipment and energy costs.